Bleaching-out dye layers



Patented Oct. 26, 1937 UNITED STATES PATENT OFFICE BLEACHING-OUT on:LAYERS No Drawing. Application September 26,- 1933, Serial No. 691,080.In Germany September 30,

6 Claims.

Our present invention relates to bleaching-out dye layers.

One of its objects is a process of preparing bleaching-out dyes. Anotherobject is the bleaching-out dye layers containing the bleaching-outdyes.

Bleaching-out dye layers are already known which have incorporatedxanthoxonium dyes containing in the 3 and 6 positions either amino 0groups or hydroxy groups.

We have found that bleaching-out dye layers having incorporated axanthoxonium dye containing in the 3 position an unsubstituted or asubstituted amino group and in the 6 position the hydroxyl group, or analkoxy group, or an aryloxy group, or an acyl group, and vice versa, aresuperior to the hitherto known bleaching-out dye layers as regards theirbleaching-out velocity and the purity of the whites.

The dyes suitable for the purpose of the invention correspond with thegeneral formula In this formula R1, R2, and Rs stand for hydrogen; analiphatic radical, for instance, methyl or ethyl; an aromatic radical,for instance, phenyl or benzyl; or an acid radical, for instance, aceticacid or benzoic acid, R4 stands for hydrogen; an

aliphatic radical, for instance, methyl or ethyl; or an aromaticradical, for instancephenyl or substituted phenyl, R5 stands for aninorganic acid radical, for instance, the radical of hydrochloric acidor sulfuric acid; or an organic acid radical, for instance, acetic acidor benzoic acid.

In the above formula the benzene nuclei may be further substituted,besides the 3 and 6 positions. Moreover, the benzene nuclei may bereplaced by other aromatic ring systems.

The dyes are obtainable by condensing monoacetyl-m-amidophenol withbenzotrichloride or a substitution product of benzotrichloride for pre-I into the required dye. Thus, for obtaining the alkoxy substituted dyesthe fluorone is treated with an alkylating agent for instance,dialkylsulfate, for obtaining aryloxy substituted dyes the flourone isphenylated in known manner, for obtaining acyl substituted dyes thefluorone is treated with the required acid chloride.

The bleaching-out dye layers are prepared in known manner by applying asolution containing the dye, a sensitizer, an acid compound and abinding agent to a suitable base.

The following examples serve to illustrate the invention, Examples 1 to5 illustrating bleaching-out dyes and Examples 6 and 7 illustratingbleaching-out dye layers.

Example 1.--3-amino 6 hydroxy 9 phenylxanthoxoniumchloride correspondingwith the may be obtained as follows:

. Grams Mono-acetyl-m-amidophenol 50 Benzotrlchloride 28 NitrobenzeneAnhydrous zinc chloride 10 are rapidly heated to C. in an oil bath, thenslowly further heated to -150 C. and kept at this temperature for about5 hours. Then the mixture is dissolved in alcohol and the nitrobenzeneis removed by distillation with water. The residue is dried on the steambath in the vacuum in the presence of phosphorus pentoxide andpulverized. 28 grams of the brown powder are mixed with 14 grams ofsodium acetate and 224 grams of acetic anhydride, and boiled for about10 minutes. After cooling the solution is cast on ice, there is addedhydrochloric acid until the solution has become acid when tested withCongo paper, then the solution is added to liter 80 C. hot water, andfiltered at 40 to 50 C. The cooled filtrate is mixed with ammonia aslong as precipitate separates, while cooling so intensely that 20 C. isnot surpassed. The precipitate is filtered and washed with a smallquantity of alcohol and acetone. The light red powder ebtained is theacetamido-phenylfluorone. By treating the acetamido-phenylfluorone withdiluted sulfuric acid the acetylamino group is saponified and the dyeobtained.

Example 2.The dye 3-acetylamino-6-methoxy-9-phenylxanthoxonium chloridecorresponding with the formula I cmoo is obtainable as follows:

3.5 grams of acetamino-phenylfluorone as obtained according to Example 1are dissolved in 20 cc. of boiling freshly distilled nitrobenzene. Thismixture is distilled until the distillate comes clear and then there areadded 1.55 grams of freshly distilled dimethylsulfate to the residue.After cooling the mixture is run into 1 liter of ether so that theprecipitate is obtained in form of a powder. The precipitate isfiltered, washed with ether and dried in the vacuum. Then the product issuspended in water and the water decanted as long as the decanted liquidyields a precipitate on the addition of common salt. The precipitatesthus obtained are collected by filtering and dried in the presence ofphosphoruspentoxide. The dry precipitate is extracted in a Soxhlet, thegreatest part of alcohol evaporated and the residue added to a mixtureof alcohol and ether. Now, there is introduced dry gaseous hydrochloricacid until the precipitate deposits, then the precipitate is filtered,washed with much ether and dried in the presence of phosphoruspentoxide.

Example 3.The dye 3-amino-6-methoxy-9- phenylxanthoxonium chloridecorresponding with the formula my \0 0CH| is obtainable when treatingthe dye obtained according to Example 2 with diluted hydrochloric aciduntil the acetylamino group is saponifled.

Example 4.The dye 3-amino-6-hydroxy-9- para-chlorophenyl-xanthoxoniumchloride corresponding with the formula zN 0 OH c.

is obtainable when working according to the method described in Example1 but using chlorobenzotrichloride instead of benzotrichloride.

Example 5.The dye 3 amino-6-hydroxy-9- methylxanthoxonium sulfatecorresponding with the formula t ill) S6411 is obtainable by condensingmono-acetyl-mamidophenyl with acetaldehyde in the presence of tintetrachloride in a manneranalogous to that described in Example 1.

Example 6.8 milligrams of 3-acetylamino-6-methoxy-9-phenylxanthoxoniumchloride,

0.2 gram of maleic acid, and 0.2 gram of diethylthiosinamine aredissolved in 50 cc. of 'a collodion solution of 3 40 cc. of a 1/250n-solution of 3-ethoxy-6- acetylamino-9-phenyl-9.lo-xanthoxoniumchloride in alcohol,

cc. of a 1/1000 n-solution of 2.7-diethoxy- 3.6 diethyl amino- 9.10carbselenonium chloride in alcohol,

2.5 grams of symmetrical diallylthiourea, and 6 drops of cone.hydrochloric acid.

This solution is applied on baryta paper provided with a coating made ofcaoutchouc containing maleic acid. After printing under a coloredpattern, fixing is effected with a mixture of benzene and anisol in theproportion of 3:1.

' What we claim is:

1. A bleaching-out dye layer comprising a binding agent, a sensitizer,an acid compound and a dye corresponding with the formula R1, R2 standfor hydrogen, or the radical of a fatty acid R3 stands for hydroxyl oran alkoxy group R4 stands for hydrogen, alkyl or an aromatic radical ofthe benzene series R5 stands for an acid radical.

2. A bleaching-out dye layer comprising a binding agent, a sensitizer,an acid compound and B-amino-G-hydroxy-9-phenylxanthoxonium chloride. Y

3. A bleaching-out dye layer comprising a binding agent, a sensitizer,an acid compound and3-acetylamido-6-methoxy-9-phenylxanthoxoniumchloride.

Schultz, Farbstoif-- 4. A bleaching-out dye layer comprising a bindingagent, a sensitizer, and an acid compound and3-amino-6-nydroxy-9-para-chlorophenylxanthoxoniumchloride.

5. A photographic material comprising a, support and applied to thissupport a bieaehing out dye layer comprising collodion.3-acetyiamino-qmethoxy-Q-phenylxanthoxoniumchlotide, maleic acid anddiethylthiosinamine.

10 6. A bleaching-out layer comprising a agent and a xanthoxonium dyesubstituted in the 3-position by an amino group, and in the 6-positionby a radical selected from the group consisting ot the hydroxyl group,an alkoxy group, an aryloxy group and an acyl group said aryl being ofthe benzene series.

JOHN EGGERT. ammo wmm'r. ALFRED mbmcn.

